The role of peritoneal granuloma inducing agents (mineral oil, pristane); endogenous and exogenous (Abelson) murine leukemia viruses; and specific genes in the pathogenesis of plasmacytomas in BALB/c mice is being studied. The antigen binding activities of myeloma proteins are being determined. Genetic markers (idiotypes, structural properties, and V-region phenotypes) associated with specific antigen-binding myeloma proteins or induced antibodies are used to identify and map immunoglobulin V-region genes.